USS North Carolina docked in Philippine port

A US submarine, the USS North Carolina, arrived at the Subic Freeport on Sunday in the thick of tensions over disputed waters in the South China Sea which have resulted in a standoff between Philippine and Chinese vessels.

The US navy attack submarine was expected for a “routine ship replenishment” and not for any other purpose, said Philippine Navy spokesman Lieutenant Colonel Omar Tonsay.

The Scarborough Shoal, claimed by both China and the Philippines, lies 234 kilometers (145 miles) from the former US naval base. During the month-long standoff, tensions have risen as both countries showed hints of military preparations, although they were calling on each other to return to diplomacy.

China once sent a warning that they are prepared to go to war and there have been rumors of war preparations. The Philippines on the other hand have worked closely with the US through its mutual defense treaty. The US remains neutral, Secretary of State Hilary Clinton said.